JPS6123972Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an emergency shutoff device for a valve body, such as a butterfly valve, which is installed in the middle of a water supply pipeline and opens and closes by rotating the valve shaft.

As an emergency shutoff device that completely closes the valve body in an emergency, such as the emergency shutoff valve described in Utility Model Application Publication No. 53-125120, the flow velocity in the pipe is set when the pipe is damaged, etc. Generally, a device is activated when the value exceeds a certain value. In this case, the valve body is rotated to the closed position via a link mechanism or an electrical weight.
In the device described in the publication, a solenoid is actuated by an electric signal, and a plurality of levers are thereby released one after another to release the lock and close the valve using a weight. Further, in this known device, after the valve is closed, the pipe line is repaired, and in order to return the valve body to its original position, it is necessary to manually return a plurality of levers one after another, which is very time-consuming.

Also, since the solenoid is located on the side of the valve box, there is a problem in installing it in a location where it may be submerged in water.
Furthermore, in such a known system, an orifice or the like is installed near the valve, and a flow meter (current meter) that can measure the flow velocity based on the differential pressure is placed to operate the device using the differential pressure. Therefore, if the downstream side of the valve is damaged, the flow rate will exceed the set value and the device will operate, but if the upstream pipe line is damaged, the flow rate (flow velocity) near the valve will not exceed the set value.

In order to solve this problem, a valve may be activated to close the pipe when the pressure inside the pipe decreases. There is a device described in Japanese Patent Publication No. 49-35294 that performs such an action. This known device supports the perforation shaft by the shaft of a diaphragm, which balances the gas pressure in the gas line with the spring pressure against it, and when the gas pressure on the diaphragm decreases due to gas leakage and the diaphragm is moved by the spring, The shaft that moves together with this is detached from the above-mentioned drilling shaft, and this drilling shaft is advanced by a spring and breaks the gas cylinder with the conical point at its tip, sending the high-pressure gas in the cylinder into the cylinder that drives the shutoff valve, and the valve body. It is activated to shut off the gas pipeline.

The above device performs an emergency shutdown due to a drop in gas pressure in the pipe, but after the emergency shutdown, it is necessary to replace the gas cylinder with a new one, and at the same time, the perforation shaft with a pointed point is returned and locked with the shaft of the diaphragm. However, these tasks must be performed manually and are extremely time-consuming. In addition, gas cylinders are likely to be made partially or completely of something like plastic because it is necessary to use a material that can be perforated, but such materials deteriorate over a long period of time, causing the sealed gas to leak and damage the cylinder. There is also the risk of causing an accident in which the valve closes even though there is no need for emergency shutoff.

In order to solve the above problems, this invention provides a swingable link lever having a hook portion that engages and disengages from a locking portion provided on an operating lever that has a weight for closing the valve body, and this link lever In this case, a piston rod fitted in a cylinder that receives water pressure in the pipeline is connected, and when the water pressure in the pipeline is normal, the link lever is set to the operating lever locking position, and when the water pressure in the pipeline is reduced, the link lever is set to the locking position. A spring is provided to move the piston rod and move the link lever to a position where its hook part is disengaged from the operating lever locking part, and the tip of the link lever is in a state where the link lever returns to the normal position due to an increase in water pressure in the pipe line. The hook part of the link lever is shaped so that it automatically engages with the locking part of the operating lever that rotates in the fully opening direction.

Although this invention has the above-mentioned configuration, one embodiment of this invention will be described below based on the attached drawings.

In the figure, 1 is a cylindrical valve box installed horizontally, and a rubber sheet 2 is attached to the inner periphery of the cylindrical valve box. Reference numeral 4 denotes a valve shaft that is horizontally attached to the valve box 1, and a disk-shaped valve body 3 is fixed to this valve shaft 4.

One end of the valve shaft 4 passes through the valve box 1 and a bracket 5 on the outside of the valve box 1, and an operating lever 7 having a weight 6 is fixed to the end thereof.

This operating lever 7 is mounted so that it faces diagonally upward when the valve body 3 is fully open, and at the lower end of this lever 7 is a piston rod 9 that projects above a hydraulic shock absorber 8 that is rotatably mounted on the bracket 5. The upper ends of the two are rotatably connected by a pin 10.

11 is a frame 12 fixed to the bracket 5
A cylinder rotatably mounted on a shaft 13,
The upper end of the piston rod 14 protruding from the upper end of this cylinder 11 is attached to a part of the link lever 16 with a shaft 1.
5, they are rotatably connected.

The link lever 16 is rotatably attached to a frame 17 whose rear end is fixed to the bracket 5 by a shaft 18. Also, this link lever 16
A hook portion 20 is formed at the tip of the actuating lever 7 to be engaged with and disengaged from a locking portion 19 provided on the side of the operating lever 7.

The lower end of the spring 21 is supported by the spring receiver on the cylinder 11, and the upper end of the spring 21 is supported by a washer 22 fixed midway on the piston rod 14.

A pressure detection pipe 23 communicating with the upper chamber of the cylinder 11 is connected to the upper side of a conduit 24. Although the pipe line 24 is shown separately from the valve box 1 in the figure, the valve box 1 is actually provided in this pipe line 24.

The other end of the valve shaft 4 passes through the other side of the valve housing 1 and enters a stand 25 provided outside thereof.
Reference numeral 26 denotes a drive device fixed to the valve box 1 via a stand 25. This drive device 26 is like a worm reducer, and its input shaft is manually operated by a handle 27 and a prime mover 28 such as a motor. Or it can be driven by power. Further, the output shaft of this drive device 26 is opposed to the end of the valve shaft 4 as a set shaft 29, and both shafts 4, 29
Clutch members 30, 31 are attached to the ends of the holder. Each of the clutch members 30, 31 is provided with an engaging pawl, and the play of the engaging pawl in the rotational direction is set to be equal to or greater than the fully open and fully closed angles of the valve body 3. There is no need to move it in the axial direction.

This invention has the above structure, and the valve body 3 in normal condition.
The position is fully open. At this time, water pressure in the conduit 24 is applied to the upper chamber of the cylinder 11 through the pipe 23, pulling down the piston rod 14 against the spring 21, and the hook 20 of the link lever 16 locks the operating lever 7 as shown in the figure. The lever 7 is fixed by engaging with the portion 19. Also, at this time, the set shaft 29
In the fully closed position, there is play between the engaging pawls of the clutch members 30 and 31, allowing the valve body 3 to rotate to the fully closed position.

When an abnormality occurs in the pipe line 24 and a part of the pipe line 24 is damaged, the pressure water in the pipe line 24 escapes to the outside of the pipe line 24, so the water pressure in the pipe line 24 decreases, and the cylinder 11
Since the pressure of the water applied to the upper chamber also decreases,
The piston rod 14 is raised by the spring 21 and rotates the actuating lever 16 upward.

Therefore, the hook portion 20 of the lever 16 comes off the locking portion 19 of the lever 7, and the lever 7 rotates together with the valve shaft 4 and the valve body 3 due to the rotational force of the weight 6, and the valve body 3 is fully closed. do.

At this time, since the engaging pawl of the clutch member 30 rotates within the range of play, it does not interfere with the rotation of the valve body 3 to the fully closed position.

In addition, in order to return the fully closed valve body 3 to the fully open position as described above, turn the set shaft 29 in the fully open direction using the handle 27 or the motor 28 to open the clutch member 3.
0 and 31 are engaged and the shaft 29 is rotated together with the valve body 3 to turn the valve body 3 to the fully open position. At this time, if the water pressure inside the pipe 24 has returned to normal, the hook 20 of the link lever 16 will engage the locking part 19 of the operating lever 7, which has rotated upward together with the valve body 3, and the valve body 3 will be fully opened. Fixed in position. Thereafter, the set shaft 29 is rotated in the opposite direction using the handle 27 or the like to return the set shaft 29 to a position where the valve body 3 is fully closed.

Although the above embodiment does not require the clutch members 30, 31 to move in the axial direction, it is possible to engage or disengage the clutch by moving either of the clutch members 30, 31 in the axial direction. May be used.

As mentioned above, when the water pressure in the pipeline decreases, the water pressure in the cylinder also decreases, so the link lever is moved by the spring, and the hook at the tip disengages from the locking part of the operating lever, causing the valve to open. Since the body is completely closed, there is no need for orifices or instruments like in conventional devices, and only one pipe for pressure detection is taken out from the conduit, so the structure is extremely simple and the operation is reliable. This device operates reliably even if any part upstream or downstream is damaged, so it can be safely used in water storage devices using pipes. When the link lever returns to its normal position due to the increase in water pressure in the pipe, insert the tip of the link lever that has a hook that engages into the locking part of the operating lever that is rotating in the fully open direction. The hook is shaped to automatically engage, so after the water pressure returns to normal after an emergency shutoff, the weighted operating lever can be set by simply turning the valve body in the fully open direction. When the shutoff valve is restored, there is no need for the operator to approach the vicinity of the valve box, and the restoration work can be performed extremely easily and quickly.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinal side view of the emergency shutoff device of this invention, and FIG. 2 is a partially longitudinal front view of the same. 3... Valve body, 4... Valve shaft, 6... Weight, 7... Operating lever, 9... Piston rod, 11... Cylinder,
16... Link lever, 19... Locking part.

Claims (1)

[Scope of utility model registration request] An operating lever is provided that rotates in conjunction with the valve stem of the valve, which opens and closes the valve body by rotating the valve stem, and this operating lever is equipped with a weight that rotates the valve body in the closing direction in an emergency to close the pipeline. The valve body is provided with a swingable link lever having a hook portion that engages and disengages from a locking portion provided on the operating lever, and the link lever is fitted with a cylinder that receives water pressure in the pipe. When the water pressure in the pipeline is normal, the link lever is set to the operating lever locking position, and when the water pressure in the pipeline is reduced, the piston rod is moved to move the link lever and its hook into the operating lever locking position. A spring is provided to move the link lever to a position where it is released from the locking portion, and the tip of the link lever is a locking portion of the operating lever that rotates in the fully open direction when the link lever returns to its normal position due to an increase in water pressure in the pipe. An emergency shutoff device with a valve body shaped so that the hook of the link lever automatically engages.